The proposed work will develop models of the anatomy that will be used to identify such anatomy in medical images. The work is focused around two specific projects: (1) the location of nodules in chest radiographs, and (2) the location of the heart walls in cardiac ultrasound data. The chest radiograph project will develop a new digital method of filtering radiographs coupled with computer algorithms to detect the images of the ribcage and solitary nodules in the filtered radiograph. The cardiac ultrasound project will utilize a model of three-dimensional shapes developed as part of this research to model the chambers of the heart as seen in three-dimensional ECG-gated ultrasound data. The result of this project will be a unique way of viewing heart motion.